1. Field of the Invention
The present invention relates to oil and gas well drilling and more particularly relates to the management of oil and gas well drilling fluids and even more particularly to a method and apparatus for transporting bulk quantities of dry drilling material to and from an oil and gas well drilling structure wherein a rigid basket houses and supports a flexible bulk bag (such as the one shown in U.S. Pat. No. Re. 34,560), the basket including a structural base for lifting from the bottom and lugs for lifting from above and a plurality of folding sides that are collapsible after the bulk bag has been emptied.
2. General Background
There are many dry powder products used as drilling mud components. Many of the products must be protected from the slightest amount of moisture in a sealed tank such as caustic soda and XCD polymer. Many of these products are not affected by moisture; such as fibers, lignite, and bentonite.
Many drilling products can be transported via bulk bag. Bulk bags are made of synthetic polymers and plastics. Bulk bags are designed with a safety factor of 5 to 1 in most cases. The bag is not guaranteed from tearing because of improper handling or from overload. The bag will also deteriorate over time as well. The bulk bag has a limited number of lifts it can endure. It is not possible for the bulk bag to safely support the drilling mud products that it carries through the numerous lifts it must endure.
The operators have palletized materials delivered to the location. The palletized materials can be stored in low overhead areas. Palletized material can be stacked on each other due to the structural strength the small bags provide through bond stacking. The primary support for lifting comes from the wooden pallet the bags sit on. The pallet can be lifted with fork trucks and pallet lifting crane devices. Once the material is used, the pallets are stacked and sent back utilizing minimum space on transport vehicles and vessels.
The wooden pallet has inherent problems. It does not protect the product from the fork truck tongs and is easily broken by improper handling. It does not give the stacked bags a total structural support necessary for handling, balancing and stacking. Pallets are manufactured using forest products, the drilling fluids industry accounting for 450,000 pallets in 1991. If the industry is going to eliminate the use of wooden pallets, paper sacks, and plastic shrink-wraps for environmental reasons, it must change to a reusable/recyclable system.
If the industry is going to change to a more ecological friendly system the bulk bag must be used. The only way the bulk bag can be used in the industry is to allow it the same luxuries the palletized material system did. This primarily being rig storage areas and rig equipment designed for palletized material and minimum space required for transporting empty pallets and sacks versus an empty tank.
A number of patents have issued which relate to pallets for transporting various products. U.S. Pat. Nos. 4,729,483; 2,956,763; 3,499,398; and 4,353,520 all show pallets having frames with sockets for accommodating the tines of a forklift and sidewalls, some of which are folding or collapsing.
U.S. Pat. Nos. 3,857,494; 3,168,060; 3,289,613; 4,295,431, and 5,078,415 all discuss pallet lifting devices with removable side supports.
A mobile carrier for gas cylinders is the subject of U.S. Pat. No. 5,078,415 issued to Norbert Goral. The '415 patent provides a mobile carrier capable of carrying a number of gas cylinders comprising a generally horizontal first support surface with at least three wheel supports rigidly attached to it, each wheel support including a rotatably mounted wheel. The wheel supports are off-set laterally relative to the first support surface, the first support surface being below the top of at least one wheel support. An upright frame rigidly connected to the first support surface extends around three sides of the carrier. A second support surface is pivotally connected to an outside edge of the first support surface along a fourth open side of the carrier. The second support surface is pivotable between an upright position, where it may be secured to the frame, and a lowered position in which the second support surface is supported on another surface so that a gas cylinder may be moved between the mobile carrier and another surface by rolling the container about its axis between the first support surface and the other support surface along the second support surface.
U.S. Pat. No. 4,729,483 issued to Donald E. Schrader provides a deck member for a storage rack in which the front and rear portions of the deck member are provided with the front and rear planar platform surfaces including correspondingly upwardly projecting transverse front and rear ridge members having a front-to-rear dimension of a storage container received on the deck member, to retain the storage container upon the deck member.
U.S. Pat. No. 4,353,520 issued to Hadar J. E. Jansson relates to an apparatus in large open goods carriers, so called container-flats, which display a loading plant and at least one wall unit, for example an end wall unit, which is fixedly retained in the loading plane for pivotal switching from a rest position, in which the wall unit is located in or parallel with the loading plane, and a working position, in which the wall unit makes substantially a right angle with the loading plane. The anchorage of the wall unit consists of a hinge means with a shaft in or on which one end of at least one torsion bar is disposed in a non-rotary manner, the torsion bar extending longitudinally with the pivotal shaft of the pivotal wall unit the other end of the torsion bar being disposed in a non-rotary manner in the loading plane, and that the torsion bar is tension-free in a position on the wall unit between its rest position and working position.
A pallet for receiving, retaining and facilitating the transportation of pressurized gas cylinders is the subject of the '431 patent issued to Lars G. Stavlo. The pallet includes three fixed, upstanding fence-like side walls and a pair of upper and lower gate members defining a fourth, openable side wall. The fixed upstanding side walls extend around three sides of the perimeter of a generally rectangular floor structure. Posts are provided at the four corners of the floor structure and extend upwardly above the top surface of the floor structure. The upper gate member is nonreleasably but movably connected to a second one of the posts. The upper gate member is movable between a retaining position extending between the first and second posts, and a loading position nested within the first of the posts. The lower gate member is pivotally connected near its lower edge to the floor structure for movement between an upstanding retaining position and a downwardly extending loading position wherein the lower gate member forms a ramp to facilitate the loading and unloading of gas cylinders onto and off of the top surface of the floor structure. A latching collar is slidably carrier on one of the first and second posts for engaging the lower gate member to releasably latch the lower gate member in its retaining position.
U.S. Pat. No. 4,292,901 issued to Clayton E. Cox provides a cornerboard for a pallet which is fabricated from a suitable material; in one embodiment it is molded of a plastic and in another it is made of sheet steel sections. The cornerboards may be provided with a variety of interlocking sections and spacer members so that packages of different sizes can be accommodated by selecting the proper length of the sections and/or spacers.
Another patent issued to Cox, U.S. Pat. No. 4,265,194 provides an improved cornerboard for a pallet wherein the main portion consists of two L-shaped metal sections with complementary tongues and slots so that the cornerboard height can be readily adjusted. The cornerboard is easily fabricated from steel sheet sections utilizing conventional bending, stamping and welding techniques.
U.S. Pat. No. 4,201,138, also issued to Clayton E. Cox, deals with an improved cornerboard for a pallet wherein conventional boards are equipped with top and bottom caps which may be fabricated of a suitable hard material such as plastic or metal. The cornerboard caps of that invention protect the ends of the cornerboards from damage and also hold them in the correct right angle alignment. Cornerboard caps may be fitted with top portions which further protect material on a pallet. In accordance with one embodiment of the invention, filler sections may be employed so that a given set of cornerboards can accept loads of different heights.
U.S. Pat. No. 3,857,494 issued to Giardini provides a modular rack assembly for storing and shipping massive metal articles which includes a rigid rectangular base having a vertically disposed leg fixed at each corner and a post member extending vertically above and supported by each leg. The legs and post members include means providing a pair of open, interfacing vertically aligned grooves at each side of the rack assembly for slidably receiving and laterally supporting the opposite ends of side members disposed on edge along each side of the rack assembly to provide a load bearing side wall at each side of the rack assembly.
A portable storage rack or pallet having foldable end frames used in the shipment and/or conveying of articles is the subject of U.S. Pat. No. 3,499,398 issued to J. M. Murray. More particularly, the '398 patent provides a storage rack or pallet including a platform with foldable end frames hingedly connected thereto, and still more particularly a storage rack or pallet having end frames movable between upright and folded positions to facilitate shipping of the frames after usage.
U.S. Pat. No. 3,401,651 issued to Roland Carlstom provides a load carrying pallet having a rectangular bottom frame, pillars located at the corners of the frame and hingedly connected to the frame and lateral supports hingedly connected to said pillars, so that the pillars with the supports may be easily swung from an upright position to a lying position upon the frame and vice versa.
A stacking frame assembly for a pallet is the subject of U.S. Pat. No. 3,289,613 issued to George Q. Evans. The '613 patent relates to a stacking frame assembly for a pallet and more particularly to a frame which is secured to a pallet whereby a pallet may be stacked on top of the frame and in which the frame is readily detachable from the pallet to which it is secured.
U.S. Pat. No. 3,168,060 issued to Arthur C. Farley relates to pallet stacking devices of the character which permit a fork lift truck to mount pallets successively on top of one another for storage of material in a depot or in a warehouse.
U.S. Pat. No. 2,956,763 issued to Nicholas A. D'Arca relates to pallets for storing and transporting articles and more particularly to improvements in collapsible and tierable pallets or tote racks.